I am not a big tool user in general. By that I mean the types of tools that supposedly help you "optimize" your website. There is no perfect page for SEO purposes, so in my opinion any tool that claims to give you information such as how many words you need here or there is simply wrong.

What most of those tools do is look at the top 10 ranking sites for a specific keyword phrase and then take averages of how many words they have in the Title tags, within the content, etc. Which to me is just silly. An average doesn't tell you anything. One page might have 1,000 words and another might have 50, but the average is then in the 500 range. That certainly doesn't mean that if you create your page to have 500 words it will somehow magically rank well.

Keep in mind that I generally only do SEO site audit reports, and high-level SEO consulting and training (as opposed to rolling up my sleeves and actually doing the SEO for clients). So I may be missing some that I previously used. Please note that while I assume that the Google tools I'm mentioning are obvious, they're so integral to my work that I'd be remiss not to mention them.

Here are the tools I use regularly to help with my SEO consulting services:

Everyone with a website today needs to be signed up here. It offers tons of useful information, but basically it helps diagnose website problems and provides messages directly from Google if a site has a major issue or penalty.

This tool sends a spider out to sites and compiles a nice spreadsheet report on the pages. It shows you Title tags, URLs, Meta Descriptions, Canonical tags, etc. Plus, it tells you about pages that may have 404 errors, redirects, and lots of other things. I usually use this when I'm starting a new site review because it helps me get an overall feel for the site and quickly shows me any major technical issues. (And I just love the tool's name.)

This one is good for seeing what sort of redirect any page may have. For SEO purposes we like to see 301 redirects rather than 302s or any other kind. It will also show if there are multiple redirects for any URL.

This is a great tool for learning about any website's backlinks. You can get a lot of that also from Google Webmaster Tools these days, but I often find different ones showing up in Ahrefs that I may not have seen in GWT. Plus, you can learn about the backlinks of competitor sites. I mainly use it to see if the website I'm reviewing has a lot of spammy links. It's especially helpful if the site has received an unnatural links warning in the GWT account. It's a great way to see the distribution of anchor text as well. This tool also has a spidering component similar to ScreamingFrog mentioned above.

This is pretty much the only tool I use or recommend for doing keyword research. Use it to learn about the types of phrases your target audience uses at Google when they're looking for what you offer on your website.

This is not so much an SEO tool as it is a way to have all my files synced across all of my computers and devices. Drive makes it easy for me to review a website and have my report in progress anytime and anywhere I need it. It also enabled me to buy an inexpensive Chromebook as my traveling laptop. All the tools and programs I use are online, so with my documents and files safely tucked away in Google Drive I'm totally in the cloud.

This is a project timer that I've been using lately. I like to keep track of how much time I spend on any client work so that I have a good idea of how to price similar jobs in the future. I've used a variety of timers in the past, but this one has become a favorite because it syncs up "in the cloud" so I can access it using any device.

Chrome Extensions (Most if not all of these are likely available as Firefox extensions as well):

This is the BEST extension ever if you're an SEO! It outlines all links on a page that have the Nofollow attribute on them. But even better is that it pops up a little window if the page you're looking at has the Noindex tag on it. You wouldn't believe how many websites I find through this extension that are inadvertently blocking all search engines from being able to index them.

This tool teaches you lots of things about a page, such as its Google Toolbar PageRank, the number of pages from the site that are indexed, a link to the page in the Wayback Machine (archive.org) and many other things. (This one will also highlight nofollow links.)

This one shows if there are any Google Analytics code errors on any given page. It can come in handy if a site appears to have lost traffic because sometimes traffic wasn't actually lost, but the Google Analytics code is missing from certain pages, or it's used incorrectly.

I use Awesome Screenshot nearly every day while doing SEO site audits to quickly and easily show what's wrong with pages on a site. You can add arrows and words, draw circles around items, etc. I basically paste them all into Evernote along with my other notes of what's wrong with a site. Then I use those notes to compile my report.

Adriel Brunson said: What a great list - I have to try Screaming Frog just because it's such a great name. Thanks Jill!

Pete Stone said: Not a bad list but a little surprised you didn't include Niels Bosma's SEO tools for excel: http://nielsbosma.se/projects/seotools/ which does several of the task you mention in one hit, all in excel and can be hooked into Google Analytics and Majestic

@Pete, not sure why you're surprised. The list is tools I use every day. Because I don't use the one you mentioned, there was no way for it to make the list!

Jonathan Jones said: I think Ahrefs is the best tool to that I've used to date, even if I'm only using the non-subscribed version. It really lets you know what links are affecting your search results.

I'd also recommend these tools:
Rank Watch
Majestic SEO

They both perform similar checks on your specified keywords on Google, Bing and Yahoo. I would say that Majestic SEO is a little better as it will also check where your back links come from (Like Ahrefs) and you can do some other cool stuff like comparing your site's data with a competitors site's data.

Sharanyan said: very nice list Jill, Try to update some short of Chrome,Firefox standalone Addons.

Phil Wollerman said: Thanks Jill! Will be spending this morning experimenting and it's great to have some guidance from an actual authority. Do you know if any tool that pulls together standard data to create client reports? I.e. a standard format that I can add an exec summary and recommendations to?

I'm finding that my reports are too complicated for clients to read, let alone understand! Not only that but they're eye-wateringly time consuming...

Jill Whalen said: No sorry, Phil, I don't. I had something like that developed for me awhile back that I use. But it's not public nor for sale!

Mandy Cochrane said: I find SEOMoz's Mozbar very useful. Too many tools to mention, a few you need to be a paid up member to use but most of them totally free. Helps me analyse many different elements of a page quickly, easily and all in one place.

Lauren Redgrave said: Jill, I think you're right - averages don't say much. But when you don't know what to do with numbers you need to switch tool. I've chosen ColibriTool and I integrated it with Google Analytics. And that was the best move I did in seo area.GA gives me numbers, averages, statistics but Colibri tells me what's going on. It was naver that easy as now.